Inertia locking system and collapsible seat with the locking system

ABSTRACT

An inertia locking system is provided with a pedestal  301  in which a substantially U-shaped receiving port  300  receiving a locked member is open toward an obliquely upper side, a latch  302  formed in a substantially reverse-J shape in a portion from a lower base portion  302   a  to a curved upper portion  302   b,  a pivot pin  303  pivoting the latch  302  to a side portion of the pedestal  301  by the lower base portion  302   a  so as to direct the curved upper portion of the latch  302  toward the receiving port  300  of the pedestal  301,  and a torsion coil spring  304  biasing the latch  302  to a lock position or an unlock position. In the structure of supporting the latch  302  so as to bias in a moving part direction at the back of the receiving port  300  of the pedestal  301  by the torsion coil spring  304,  there is provided the latch  302  having a jaw portion  302   c  with which a locked member  1   a  inserted to the receiving port  300  of the pedestal  301  is brought into contact so as to kick, and the jaw portion which projects from the lower base portion  302   a  to an inner side of a bottom line of the receiving port  300,  whereby the locked member  1   a  can be securely gripped and held by the latch  302  in accordance with a simple operation.

TECHNICAL FIELD

[0001] The present invention relates to an inertia locking system in which a latch is operated by a torsion coil spring due to an inertia force so as to grip and hold a locked member when the locked member is brought into contact therewith, and an improvement of a collapsible seat provided with the inertia locking system.

BACKGROUND ART

[0002] In general, as a seat for being equipped in a station wagon or the like, there is a seat which is constituted by a seat cushion 1 having a front face upward substantially C-shaped leg portion 1 a capable of being stood on a lower stage portion surface f₁ of a vehicle body floor F in a lower portion close to a front side as shown in FIG. 1, and a seat back 2 placed so as to be tiltable by axially supporting a bracket 2 a protruding from a lower portion side of the seat back 2 to an upper stage portion surface f₂ of the vehicle body floor F by a supporting shaft 2 b, axially supports and connects a curved arm 1 b extending to a rear portion side of the seat cushion 1 to a portion close to a lower side of a side portion of the seat back 2 by a supporting shaft 1 c, and can jump up the seat cushion 1 including the leg portion 1 a by the curved arm 1 b.

[0003] In the collapsible seat, an inertia locking system 3 gripping and holding the leg portion 1 a of the seat cushion 1 in a lower line of the shaft is mounted so as to be placed in the lower stage portion f₁ of the vehicle body floor F.

[0004] The inertia locking system 3 is conventionally provided with a pedestal 31 in which a substantially U-shaped receiving port 30 receiving the leg portion 1 a of the seat cushion (not shown) in the lower line of the shaft is open toward an obliquely upper side, a latch 32 formed in a substantially reverse-J shape from a lower base portion 32 a to a curved upper portion 32 b, a pivot pin 33 pivoting the latch 32 to a side portion of the pedestal 31 by the lower base portion 32 a so as to direct the curved upper portion 32 b of the latch 32 toward the receiving port 30 of the pedestal 31, and a torsion coil spring 34 spring biasing the latch 32 to a locking position or an unlocking position, as shown in FIG. 8.

[0005] In the structure, the torsion coil spring 34 fits a coil spring portion 34 a onto an axis of the pivot pin 33, fastens one spring end 34 b to a projection piece 35 protruding out from the side portion of the receiving table 31 at a position close to a rear side of the pivot pin 33, and fastens another spring end 34 c to a projection piece 36 protruding out from an upper side of the latch 32, thereby being mounted.

[0006] In the inertia locking system, in order to dissolve a troublesome in use of canceling the lock, the latch 32 is assembled so as to be supported and biased in a moving apart direction at the back of the receiving port 30 of the pedestal 31 by the torsion coil spring 34 at a normal time. On the contrary, at a time of collision or the like, the latch 32 is operated by the torsion coil spring 34 in such a manner as to move a position of center of gravity corresponding to a fastening point of the spring end 34 c to a front side on the basis of an inertia force, thereby being assembled so as to grip and hold the leg portion 1 a of the seat cushion 1 positioned within the receiving port 30 by the latch 32.

[0007] In this case, in the seat provided with the seat cushion 1 capable of being jumped up mentioned above, since an offset exists between a center of rotation given by the supporting shaft 1 c and a center of gravity of the seat cushion 1, the rotational force by which the seat cushion 1 jumps up is generated, at a time when a sitting person does not exist due to the collision or the like. On the contrary, in the inertia locking system 3 mentioned above, since the latch 32 is operated after the inertia force generated by the collision or the like is applied, a lot of time is required until the latch 32 engages with the leg portion 1 a of the seat cushion 1, so that there is generated a matter that the leg portion 1 a of the seat cushion 1 can not e gripped and held by the latch 32.

[0008] Further, since the latch 32 is supported so as to be biased in the moving apart direction at the back of the receiving port 30 of the pedestal 31 by the torsion coil spring 34 at the normal time, foreign materials and the like are attached around an axis of the pivot pin 33, and it can not be known in advance whether or not the latch 32 becomes in a state that it can not rotate.

DISCLOSURE OF THE INVENTION

[0009] An object of the present invention is to provide an inertia locking system which can securely grip and hold a locked member by a latch on the basis of a simple operation.

[0010] Further, another object of the present invention is to provide a collapsible seat which can securely prevent a seat cushion from being kicked up accompanying with a collision or the like by an inertia locking system.

[0011] In an inertia locking system in accordance with the present invention, there is provided an inertia locking system comprising:

[0012] a pedestal in which a substantially U-shaped receiving port receiving a locked member is open toward an obliquely upper side;

[0013] a latch formed in a substantially reverse-J shape in a portion from a lower base portion to a curved upper portion;

[0014] a pivot pin pivoting the latch to a side portion of the pedestal by the lower base portion so as to direct the curved upper portion of the latch toward the receiving port side of the pedestal;

[0015] a torsion coil spring having a coil spring portion fitted onto an axis of the pivot pin, one spring end fastened to the side portion of the pedestal at a position close to a rear side of the pivot pin, and another spring end fastened to the upper side of the latch; and

[0016] the latch being supported so as to be biased in a moving part direction at the back of the receiving port of the pedestal by the torsion coil spring,

[0017] wherein the latch is provided with a jaw portion with which the locked member inserted to the receiving port of the pedestal is brought into contact so as to kick, and the jaw portion projects from the lower base portion to an inner side of a bottom line of the receiving port.

[0018] In accordance with the inertia locking system, since the latch is provided with a jaw portion with which the locked member inserted to the receiving port of the pedestal is brought into contact so as to kick, and the jaw portion projects from the lower base portion to an inner side of a bottom line of the receiving port, it is possible to immediately lock the locked member at a time when the locked member is brought into contact with the jaw portion of the latch, and on the contrary, since the latch is operated together with the attaching and detaching operation of the locked member, there is no troublesome in use of canceling the lock, and it is possible to prevent the matter that the latch can not be rotated due to the attachment of the foreign materials or the like to the portion around the axis of the pivot pin from being generated.

[0019] In accordance with the present invention, there is provided a collapsible seat comprising:

[0020] a seat cushion provided with a front face upward substantially C-shaped leg portion capable of being stood on a lower stage portion surface of a vehicle body floor in a lower portion close to a front side;

[0021] a tiltable seat back axially supported and placed to an upper stage portion surface of the vehicle body floor in a lower portion side;

[0022] the seat cushion being axially supported and connected to a portion close to a lower side of a side portion of the seat back by a bracket arm extending to a rear portion side; and

[0023] the seat cushion including the leg portion being provided so as to be capable of being jumped up by the bracket arm,

[0024] wherein the seat is provided with an inertia locking system in which there are provided a pedestal in which a substantially U-shaped receiving port receiving a leg portion of the seat cushion in a lower line of an axis is open toward an obliquely upper side, a latch formed in a substantially reverse-J shape in a portion from a lower base portion to a curved upper portion, and provided with a jaw portion with which the lower line of the axis of the leg portion inserted to the receiving port of the pedestal is brought into contact so as to kick in such a manner as to project from the lower base portion to an inner side of a bottom line of the receiving port, a pivot pin pivoting the latch to a side portion of the pedestal by the lower base portion so as to direct the curved upper portion toward the receiving port side of the pedestal, and a torsion coil spring having a coil spring portion fitted onto an axis of the pivot pin, one spring end fastened to the side portion of the pedestal at a position close to a rear side of the pivot pin, and another spring end fastened to the upper side of the latch, and the latch is supported so as to be biased in a moving part direction at the back of the receiving port of the pedestal by the torsion coil spring, in a lower stage portion surface of the vehicle body floor.

[0025] In accordance with the collapsible seat, it is possible to securely lock by the inertia locking system so that the seat cushion does not jump up due to the collision or the like, and on the contrary, since the latch is operated together with the attaching and detaching operation of the leg portion of the seat cushion, there is no troublesome in use of canceling the lock of the inertia locking system, and it is possible to prevent the matter that the latch can not be rotated due to the attachment of the foreign materials or the like to the portion around the axis of the pivot pin from being generated, so that it is possible to construct a user friendly structure.

[0026] The other features than the features mentioned above will be apparent in an embodiment in accordance with the present invention described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 is a schematic view showing a collapsible seat provided with an inertia locking system in accordance with the present invention;

[0028]FIG. 2 is a schematic view schematically showing a structure of the inertia locking system provided in the collapsible seat in FIG. 1;

[0029]FIG. 3 is a schematic view showing the structure of the inertia locking system in FIG. 2 in detail;

[0030]FIG. 4 is a schematic view showing the inertia locking system in FIG. 2 on the basis of an initial operation state;

[0031]FIG. 5 is a schematic view showing the inertia locking system in FIG. 2 on the basis of a lock operation state;

[0032]FIG. 6 is a schematic view showing the collapsible seat provided with the inertia locking system in accordance with the present invention on the basis of a collapsed state;

[0033]FIG. 7 is a schematic view showing a collapsible seat in accordance with a general embodiment; and

[0034]FIG. 8 is a schematic view schematically showing a structure of an inertia locking system in accordance with the conventional art.

EMBODIMENT FOR CARRYING OUT THE INVENTION

[0035] A description will be given below of an embodiment with reference to FIGS. 1 to 6. The illustrated embodiment is applied to an inertia locking system 3 preventing a seat cushion 1 from being jumped up which is provided in a collapsible seat assembled by a seat cushion 1 and a seat back 2 in the same manner as the seat in FIG. 7. In the structure, constituting parts in common with the parts shown in FIG. 7 will be described by using the same reference numerals.

[0036] The collapsible seat is constituted, as shown in FIG. 1, by a seat cushion 1 provided with a front face upward substantially C-shaped leg portion 1 a capable of being stood on a lower stage portion surface f₁ of a vehicle floor F in a lower portion close to a front side, and a seat back 2 placed in a tiltable manner by axially supporting a bracket 2 a protruding out from a lower portion side of the seat back 2 to an upper stage portion surface f₂ of the vehicle body floor F by a supporting shaft 2 b, and is structured such that a curved arm 1 b extending to a rear portion side of the seat cushion 1 is axially connected to a portion close to a lower side of a side portion of the seat back 2 by a supporting shaft 1 c, and the set cushion 1 including the leg portion 1 a can be jumped up by the curved arm 1 b.

[0037] In the structure, the leg portion 1 a of the seat cushion 1 is formed by bending a metal round pipe in a substantially C shape directed to a front face upper side, and is provided so as to be received in a lower portion side of the seat cushion 1 by axially supporting and connecting both axial ends to both sides of the lower portion in the seat cushion 1 by a supporting shaft (not shown). As the curved arm 1 b, there is placed a structure formed in a substantially reverse-L shape which is obliquely curved in correspondence to an angle of incline of the seat back 2 from a side fixed to the side portion of the seat cushion 1 to the side portion of the seat back 2 by the supporting shaft 1 c.

[0038] The inertia locking system 3 is assembled, as shown in FIGS. 2 and 3, by a pedestal 301 in which a substantially U-shaped receiving port 300 receiving the leg portion 1 a of the seat cushion by an axial lower line is open toward an obliquely upper side, a latch 302 formed in a substantially reverse-J side elevational shape from a lower base portion 302 a to a curved upper portion 302 b, a pivot pin 303 pivoting the latch 302 to a side portion of the pedestal 301 by the lower base portion 302 a so as to direct the curved upper portion 302 b of the latch 302 toward the receiving port 300 of the pedestal 301, and a torsion coil spring 304 having a coil spring portion 304 a fitted onto an axis of the pivot pin 303, one spring end 304 b fastened to the side portion of the pedestal 301 at a position close to a rear side of the pivot pin 303, and another spring end 304 c fastened to the upper side of the latch 302.

[0039] In the structure, as the latch 302, there is provided a structure having a jaw portion 302 c with which the leg portion 1 a of the seat cushion entering into the receiving port 300 of the pedestal 301 (not shown, and so forth) is brought into contact so as to kick in a state of being biased in a moving part direction at the back of the receiving port 300 of the pedestal 301 by the torsion coil spring 304, as shown in FIG. 2. In this structure, the jaw portion 302 c is protruded to an inner side of a bottom line of the receiving port 300 from the lower base portion 302 a. The jaw portion 302 c of the latch 302 forms a part of the hook gripping the leg portion 1 a of the seat cushion by being provided so as to be continuously connected to the curved upper portion 32 b by a curved surface.

[0040] In the inertia locking system 3, as shown in FIG. 3, the receiving port 300 is formed by providing with a substantially U-shaped clip 305 obtained by making the open port a little narrower than a diameter of axis of the metal round pipe so as to deflect and curve both open edges to an outer side. This clip 305 is provided by being engaged with and fixed to slits 301 a and 301 b of the pedestal 301 installed and fixed to the vehicle body floor F by retainer hooks 305 a and 305 b. The torsion coil spring 304 is provided by hooking one spring end 304 b to a stop rod 306 protruding from the pedestal 301 so as to fasten and inserting and engaging another spring end 304 c to a protrusion piece 302 d protruding from the side portion of the latch 302 so as to fasten.

[0041] In the collapsible seat provided with the inertia locking system 3 structured in the manner mentioned above, when moving the axial lower line of the leg portion 1 a within the receiving port 300 for the purpose of placing the leg portion 1 a of the seat cushion in a standing manner, the axial lower line of the leg portion 1 a is at first brought into contact with the curved surface of the jaw portion 302 c so as to kick it as shown in FIG. 4 because the jaw portion 302 c is positioned so as to protrude to the inner side of the bottom line of the receiving port 300 from the lower base portion 302 a as shown in FIG. 2. Accordingly, the latch 302 is operated so as to immediately move the position of center of gravity corresponding to the fastening point of the spring end 304 c to the front side by the torsion coil spring 304 due to an inertia force of the leg portion.

[0042] In accordance with the operation of the latch 302, as shown in FIG. 5, since the latch 302 grips the axial lower line of the leg portion 1 a from the upper side by the curved upper portion 302 b at the same time of receiving the leg portion 1 a of the seat cushion in the inner portion of the receiving port 300, it is possible to lock the leg portion 1 a of the seat cushion to the inner portion of the receiving port 300 due to an elastic pressure of the coil spring 304.

[0043] On the contrary, at a time of taking out the leg portion 1 a of the seat cushion from the inertia locking system 3, since the leg portion 1 a of the seat cushion moves along the curved surface of the curved upper portion 302 b in accordance that a passenger lifts up the seat cushion, the latch 302 is operated by the torsion coil spring 304 in such a manner as to move the position of center of gravity corresponding to the fastening point of the spring end 304 c to the back side, and is automatically returned to the initial position in such a manner as to be supported in a biased manner in the moving apart direction at the back of the receiving port 300 of the pedestal 301 by the torsion coil spring 304.

[0044] Accordingly, it is possible to immediately lock the leg portion 1 a so that the seat cushion does not jump up at a time of collision or the like. On the contrary, since the latch 302 is together operated accompanying with attaching and detaching the leg portion 1 a of the seat cushion, there is no troublesome matter in view of usability for canceling the lock of the inertia locking system 3. Further, it is possible to prevent the matter that the latch 302 can not rotate due to the foreign materials attached around the axis of the pivot pin 303 from being generated.

[0045] The collapsible seat mentioned above can be collapsed so 12 as to recline the seat back 2 to the upper stage portion f₂ of the vehicle body floor F, overlap the seat cushion 1 on the seat back 2 and overlap the leg portion 1 a on the bottom portion of the seat cushion 1, as shown in FIG. 6.

[0046] In this case, the description is given of the embodiment mentioned above in the case that the inertia locking system 3 is provided in the collapsible seat, however, the structure is not limited to this collapsible seat, and the inertia locking system 3 can be widely applied to a mechanism for gripping and holding various kinds of locked members.

[0047] In the above description, terms and expressions used in the present specification are only employed for simply describing, and do not limit the contents of the present invention. If there are used restrictive terms and expressions, they do not intend to exclude equivalent structures to the present embodiment mentioned above or a part thereof. Accordingly, various modifications can be added within the scope of the present claimed invention. 

What is claimed is:
 1. An inertia locking system comprising: a pedestal in which a substantially U-shaped receiving port receiving a locked member is open toward an obliquely upper side; a latch formed in a substantially reverse-J shape in a portion from a lower base portion to a curved upper portion; a pivot pin pivoting the latch to a side portion of the pedestal by the lower base portion so as to direct the curved upper portion of the latch toward the receiving port side of the pedestal; a torsion coil spring having a coil spring portion fitted onto an axis of the pivot pin, one spring end fastened to the side portion of the pedestal at a position close to a rear side of the pivot pin, and another spring end fastened to the upper side of the latch; and the latch being supported so as to be biased in a moving part direction at the back of the receiving port of the pedestal by the torsion coil spring, wherein the latch is provided with a jaw portion with which the locked member inserted to the receiving port of the pedestal is brought into contact so as to kick, and the jaw portion projects from the lower base portion to an inner side of a bottom line of the receiving port.
 2. A collapsible seat comprising: a seat cushion provided with a front face upward substantially C-shaped leg portion capable of being stood on a lower stage portion surface of a vehicle body floor in a lower portion close to a front side; a tiltable seat back axially supported and placed to an upper stage portion surface of the vehicle body floor in a lower portion side; the seat cushion being axially supported and connected to a portion close to a lower side of a side portion of the seat back by a bracket arm extending to a rear portion side; and the seat cushion including the leg portion being provided so as to be capable of being jumped up by the bracket arm, wherein the seat is provided with an inertia locking system in which there are provided a pedestal in which a substantially U-shaped receiving port receiving a leg portion of the seat cushion in a lower line of an axis is open toward an obliquely upper side, a latch formed in a substantially reverse-J shape in a portion from a lower base portion to a curved upper portion, and provided with a jaw portion with which the lower line of the axis of the leg portion inserted to the receiving port of the pedestal is brought into contact so as to kick in such a manner as to project from the lower base portion to an inner side of a bottom line of the receiving port, a pivot pin pivoting the latch to a side portion of the pedestal by the lower base portion so as to direct the curved upper portion toward the receiving port side of the pedestal, and a torsion coil spring having a coil spring portion fitted onto an axis of the pivot pin, one spring end fastened to the side portion of the pedestal at a position close to a rear side of the pivot pin, and another spring end fastened to the upper side of the latch, and the latch is supported so as to be biased in a moving part direction at the back of the receiving port of the pedestal by the torsion coil spring, in a lower stage portion surface of the vehicle body floor. 